<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		
		<script type="text/javascript">
			function cal(type) {
				var num1 = document.getElementById("num1").value;
	        	var num2 = document.getElementById("num2").value;
	        	var result;
	        	switch(type) {
	        		case "+":
	        			result = parseInt(num1) + parseInt(num2);
	        		break;
	        		case "-":
	        			result = parseInt(num1) - parseInt(num2);
	        		break;
	        		case "*":
	        			result = parseInt(num1) * parseInt(num2);
	        		break;
	        		case "/":
	        			result = parseInt(num1) / parseInt(num2);
	        		break;
	        		default:
	        			console.log("default");
	        		break;
	        	}
	        	
	        	var resultInput = document.getElementById("result");
	        	resultInput.value = result;
			}
		</script>
	</head>

	<body>
		<table>
			<tr>
				<td><img src="shop.jpg" /></td>
				<td colSpan="3">购物简易计算器</td>
			</tr>
			<tr>
				<td>第一个数</td>
				<td colSpan="3">
					<input type="text" id="num1" />
				</td>
			</tr>
			<tr>
				<td>第二个数</td>
				<td colSpan="3">
					<input type="text" id="num2" />
				</td>
			</tr>
			<tr>
				<td>
					<input type="button" value=" + " onclick="cal('+')"/>
				</td>
				<td>
					<input type="button" value=" - " onclick="cal('-')"/>
				</td>
				<td>
					<input type="button" value=" * " onclick="cal('*')"/>
				</td>
				<td>
					<input type="button" value=" / " onclick="cal('/')"/>
				</td>
			</tr>
			<tr>
				<td>计算结果</td>
				<td colSpan="3">
					<input type="text" id="result" />
				</td>
			</tr>
		</table>
	</body>
</html>